Version 0.92:
* change breath_mark tag to up_bow tag when score is saved.
* ignore vowel reduction flag before macron.
* fix many bugs.

Version 0.91:
 * add clef type selector to XML save function.
 * integrate chained vowels to one vowel.
 * expand score flag to 8-bit.
 * add new context: distance between consonant and vowel.
 * fix many bugs.

Version 0.90:
 * released in SourceForge.
